Apparatus for cracking hydrocarbon oils



July 2 1929 H. L. PELZER 1 1.719.486

APPARATUS FOR CRACKING HYDROCARBON OILS Filed April 16 1927 'v ii.

nur/1an ATTORNEYS Patented July 2, 1929. y

UNITE-D vSTATES 1,719,486 PATENT OFFICE.

HARRY L. PELZER, OF HIGHLAND, INDIANA, ASSIGNOR TO SINCLAIR REFINING COIVL,

PANY, OF NEW YORK, N.' Y.,

A CORPORATION OF MAINE.

APPARATUS FOB `CRACKING HYDROCARBON ILS.-

Application led April 16, 1927. Serial N0. 184,296.

This invention relates to improvements in apparatus for distilling under pressure heavier and higher boiling hydrocarbon oils, such as gas oil, for the production therefrom of lighter and lower boiling hydrocarbon c oils, such as' gasoline and gasolinefcontaining distillates.

In one advantageous method of carrying out such pressure distillation, the charge of '10 heavier' oilin the still is circulated4 through a bed of finely divided, absorbent material,

such as fullers earth, during the distillation operation. This invention relates particularly to an improved support for the bed'of absorbent material in such operations.

For carrying out such operations,l it is desirable that the support be :of a character to retain the finely divided material without unnecessarily restricting the flow of oil therethrough. Likewise, the support must Abe of sufficient strength not only to carry the weight of the bed of absorbent material but also to withstand the additional stress inci- -dent to operation. 'Freedom from clogging due to material deposited in or absorbed by the bed of absorbent material is also a desirable attribute of such support. The support, .moreove`r, should be of such a character as not to render any substantial portions of the bed lor absorbent material ineffective. f This invention provides an improved support which satisfies these requirements and which has several important advantages.

The improved, support of the present invention is made up ofone or more screens arranged between gratings made up of strips arranged edgewise with reference to the screen or screens. The mesh of the screen or screens is proportioned in accordance with '40 the degree of subdivision of the material to be supported. The screen or screens are car` ried bfy the grating on which they rest; the edgewlse arrangement of the strips making upthis grating `permits development of` a maximum of .strength with a minimum of resistance to flow. i The screens areheld in place on the supporting grating by the over-.

lying grating of similar construction, and this overlying rating also assists in retarding Yclogging o? the screen or screens and in preventing `disturbance of the arrangement of the bed of absorbent material on the screens without interferin with the efectiveness of portions of the d of absorbent material.

The invention will be further described in connection with the accompanying drawings, in which one form of apparatus embodying the invention is illustrated in a somewhat conventional and diagrammatic manner. In the accompanying drawings: y

Fig. 1 is an elevation, partly in section and with parts broken away, of a circulatory pressure still embodying this invention;

Fig. 2 is a section of the bulksupply drum shown in Fig.` 1;

Fig. 3 is an enlarged, detailed View of a portion of a support embodying. thevinvention, and

Fig. 4 is an enlarged plan of a portion of the grate forming the upper and lower cle- Inents of the support illustrated in Fig. 3. i

The pressure still illustrated is made up of a bulk supply tank 1, a battery of heating tubes 2, and circulating connections 3, 4 and j5 including a circulating pump G. A body of absorbent material 7, fullers earth for rexample, 1s arranged on a support 8, within the bulk supply drum 1. A reflux tower' 9 is arranged above the bulk suppl drum- 1. Vapors from the bulk supply rum enter the reux tower through connection 10; va pors from the reflux tower pass through connection 11 and valve'12, by which the pressure in the system may be regulated, to the condenser 13. This condenser discharges into the receiver 14. The distillate product is discharged from the receiver through connection 15.and uncondensed vaporsand gases through connection 16. `Fresh oil to be sup. plied to the operation is introduced into the -upper end of the reflux tower 9 through connection 17. Reflux condensate and admixed fresh oil flow from the lower end of the reflux tower back to the pressure still through connection 18. Connection 19 is provided` for discharging pitchvladen oil during operation,^and .connection 20 is provided for pumping out the still at the end kof a run and for initially `charging it at the begin- I ning of a run. A part of the Jfresh oil supplied to the operation may be introduced through the bearings of the circulating pump 6 for ,cooling and lubrication through connection 21. l

In operation, to produce a gasoline-containing pressure distillate from gas oil,'for

example, the charge of oil is circulated from beneath the bedof absorbent material in the bulk supply drum upwardly through the battery of heating tubes and back to the bulk supply drum. The oil may be heated, for example, to a temperature between about 750O F. and 800o F. as it leaves the battery 5 of heating tubes. The supply of fresh oil and the discharge ot' pitch laden oil are, with advantage, regulated to maintain the concentration of pitch constituents below saturation in the oil entering the battery of l0 heating tubes, The vapors liberated in the bulk supply7 drum escape to the reflux tower where the heavier portions are condensed by heat exchange with the incoming fresh oil. v'lhe reflux condensate and admixed unvaporized fresh oil are returned to the still charge circulating through thebattery of heating tubes. The vapors remaining nneondensed in the reflux tower are taken otl and condensed to form the distillate product. The pressure in the system, may,

for example, be maintained in the neighborhood of from 100 to 150 pounds per square inch.

The bed ot' absorbent material in the bulk supply drum of the pressure still may be made up, for example, of fuller-s earth of from 16 to 3() mesh. In the still illustrated the bulk supply drum, may, for example, be about nine feet in diameter and about thirty feet long, and the bed of absorbent mai terial may be from ten to eighteen inches deep. Such a bed of fullers earth may weigh, for example, from four to seven tons or more. A e

The improved support ot the present invention is illustrated in more detail in Fig. 3, this being an enlarged section of a portion of the .support designated 8 in Figs. l and 2. y This support is made up of two gratings and three interposed screens. The screens are wire mesh screens of ordinary construction. In the arrangement illustrated, the upper-and lower screens-may, for example, be of 20 mesh and the middle screen of 7 or 8 mesh. The construction ofthe gratings is better illustrated in Fig. 4. The gratings are made up of a series of strips, alternate strips being straight and those in between being arranged to space the alternate strips, the entire grating being held together by riveting or spot welding at the points Where these strips come together. In the composite support, the strips forming the grating are arranged edgewise with reference to the interposed screens. IVhile the overlying grating has several important advantages, it will be apparent that'. the lower grating and the superposed screen embody several of the advantages otl the invention. rl`he lower grating and superposed screen. for example, may be used in connection with other means for retaining the screen on the grating or for preventing disturbance of the earth bed, or the upper' grating may be omitted. It will be appreciated that the exact number and arrangement of the screens and the eX- act construction and arrangement of the gratings may vary. The form of the invention illustrated, however, has been found particularly advantageous.

The invention is also useful in connection with pressure stills differing in construction and arrangement from the particular type in connection with which it has been more particularly described and illustrated.

I claim:

l. In oil stills in which the charge is eir-l culated through a bed of finely divided material, an improved support tor the bed of finely divided material comprising a pair of gratings and an interposed screen, said gratings being made up of strips arranged edgewise with reference to the interposed screen.

2. In oil stillsl in which the charge is circulated through a bed ot' finely divided material, an improved support for the bed of finely divided material comprising a screen and a supporting grating beneath the screen, said grating being made up of strips arranged edgewise with reference to the screen.

Vr`In testimony whereof, I have subscribed my name.

HARRY L. PELZER. 

